Enabling a vehicle to follow closely behind one vehicle safely through partial or full automation has significant fuel savings, safety, and/or labor savings benefits, but is generally unsafe when a driver tries to do this manually. Presently, during normal driving, vehicle motion is controlled either manually, by a driver, or by convenience systems, such as cruise control or adaptive cruise control. The various types of cruise control systems control vehicle speed to make driving more pleasurable or relaxing, by partially automating the driving task. Some of these systems use range sensors and/or vehicle sensors to control the speed to maintain a constant headway relative to the leading vehicle (also referred to herein as a front vehicle). In general, these cruise control systems provide minimal added safety, and do not have full control of the vehicle (in terms of being able to fully brake or accelerate).
Driver control does not match the safety performance of even current systems, for several reasons. First, a driver cannot safely maintain a close following distance. In fact, the relatively short distances between vehicles necessary to get any measurable fuel savings results in an unsafe condition if the vehicle is under driver control, thereby risking a costly and destructive accident. Further, the driver is not as capable of maintaining an optimal headway as an automated system is. In fact, a driver trying to maintain a constant headway often causes rapid and large changes in command (accelerator pedal position for example), resulting in a loss of efficiency.
Thus, it would be desirable to have reliable and economical at least semi-automated vehicular convoying/platooning systems which enable vehicles to follow closely together in safe, efficient, and convenient manner.
Moreover, it is important to provide users with a pleasant user experience, particularly because drivers may not favor using the methods and systems described herein if they do not enjoy using them. As such, systems that do not cause unnecessary faults are needed in the art.